Apparatus for continuous edible oil finishing



APPARATUS FOR CONTINUOUS EDIBLE oIL FINIsHING Filed March 28, 1960 Aug.27, 1963 w` A. GRAHAM ETAL 2 Sheets-Sheet 1 Aug 27, 1953 A w. A. GRAHAMx-:TAL 3,102,062

APPARATUS FOR CONTINUOUS EDIBLE OIL F'INISHING Filed March 28, `1960 2Sheets-Sheet 2 United States Patent O 3,102,062 APPARATUS FR CONTINU UUSEEESLE OIL FNISHNG Ward A. Graham, Kansas City, Mo., and (irlanda Webb,

Jr., Prairie Village, Kans., assignors to Stratford EnginearingCorporation, Kansas City, Mo., a corporation of Delaware Filed Mar. 28,1960, Ser. No. 17,846 2 Ciaims. (Cl. 159-3) This invention relates toappanatus for finishing edible oils and refers more particularly to suchmethods and apparatus for deaeration, dehydration, deodorization,distillation (including fatty acid removal) and color improvement ofrefined edible oils such as soybean oil, cottonseed oil, peanut oil,linseed oil, castor oil, fish oils, animal oils, etc.

At the present time, refined edible oils are nished by batch, improvedbatch, semi-continuous, or continuous treatment employing conventionalvacuum drying and steam stripping techniques. `In these knownconventional systems, nished oils meeting odor, taste and colorstability requirements of the food, food processing, drug and other oilconsuming industries are achieved through the use of high temperature,low absolute pressures and relatively large qnantities of strippingsteam. One prominent limiting feature of these conventional systems isthe relatively lo'w oil-steam interfacial surface area exposed totreating conditions and the required treating time accordinglynecessary, Another limiting feature is the inability to achieve a highdegree of uniformity in the treated oil due to limitations of surfacearea control. As a result of these limitations, deaeration, dehydration,distillation and deodorization of the oils are relatively ineiiicientlyperformed. Deodorization in the industry is accomplished in complicated,expensive equipment requiring excessive time with relatively unreliableproduct :achievement of standards. Deaerating and deodorizing equipmentin the industry are space consuming, complicated to operate andmaintain, reqnire excessive instrumentation, are often not fullyautomatic and often require excessive operator atten,

tion. `Conventional deaerating and deodorizing equipment is `alsodiflicult to clean and repair.

Therefore, an object of the instant invention is to provide a continuousedible oil finishing process with improved deaerating, dehydrating,distilling and deodorizing steps or stages, including fatty acid removaland improved apparatus for performing such steps.

Another object of the invention is to provide deaerating, deodorizing,distilling and dehydrating apparatus for finishing edible oils which issimple to operate and maintain, takes up a minimum of space, requires aminimum of instrumentation, is fully automatic, and which requires aminimum of operator attention.

Another object of the invention is to provide apparatus for deaerating,dehydrating, distilling and deodorizing edible oils wherein theequipment is readily accessible in all parts thereof for cleaning orrepair.

Another object of the invention is to provide methods of and apparatusfor deaenating, dehydrating, distilling and deodorizing edible oils-wherein less steam is required to do` an equivalent finishing job tothat presently performed, while the same quantity of steam permits abetter job to be done.

Another object of the invention is to provide methods of and apparatusfor deaeration, dehydration, distilling and deodorization of edible oilsin the finishing process wherein the deaeration, dehydration,distillation and deodorization are far more thorough, accomplished inless time in less complicated equipment and wherein far more reliableproduct achievement of standards is realized.

lh-Zhz Patented Aug. 27, 1963 Still another object of the invention isto provide methods of and apparatus for finishing edible oils whereinthere is substantially less chance of off-specification product andwherein -a great uniformity of exposure of the edible oil is achieved inthe linishing process.

-Other and further objects of the invention will appear in the course ofthe following description thereof.

ln the drawings, which form a part of the instant specification and areto be read in conjunction therewith, embodiments of the invention tareshown and, in the various views, like numerals rare employed to indicatelike parts.

lFIG. 1 is a schematic flow diagram of an apparatus` embodying theinventive process.

FIG. 3 is a side sectional view of the rotatable spray head of FIG. 2,the view enlarged and partial.

FIG. 4 is a view taken along the line 4 4 of PIG. 3 in the direction ofthe arrows.

FIG. 5 is a view similar to that of |FIG. 3, but showing a static,nonrotating spray head adaptable for use in the flash evaporator shownat 19, 42 and 61 of FIG. 1.

Vegetable oils are conventionally obtained by either expression orsolvent extraction. Description of typical expression and solventextraction processes may be found in The `Chemical Process Industries,R. Norris Shreve, 2nd ed., 1956, McGraw-Hill Book Company, Inc. Crudeoils obtained by either of these processes are conventionally purified.A recently developed liquid-liquid extraction process for refining ofvegetable and animal fats and oils is superseding to a certain extentthe once widely used alkali purification. IIn the alkali method, thefree fatty acids are neutralized with caustic soda or soda-ash, formingsoaps which are removed by centrifuges or filters and the fatty acidsrecovered. Oils are subsequently Water washed for final removal of soapland unreacted caustic.

Referring to the drawing, at 10 is schematically indicated conventionalprocesses of caustic refining, including water wash. This step does notform a part of the instant invention as it is conventional. The oil tobe finished is passed through line y1.1 to a vessel 212 wherediatomaceous earth, activated carbon, clay, filter aid or otherdecolorizing agent is added, typically through a star feeder 12a, mixedby rotor 12b. The oil is then passed through line 13 to a primary earthstrainer `14 or filtering device vvhere overlylarge particles of thediatofaceous earth, lter aid or activated carbon are removed. Fromstrainer 14, the oil is passed through line 15 toheat exchanger 16 wherethe temperature of the oil is raised to that necessary for subsequenttreatment. For example, in the case of soybean oil, this temperaturewould be approximately 145 The oil is then passed by line 117 throughfilter 18 which removes particles larger than 0.0011 to 0.015 inchdiameter, depending on the rotor orifice to be described. -Generally itis preferred to stay 0.0011 to 0.005 inch under the rotor orifice.

Flash evaporator vessel 19 has a spray distribution head or rotor 20mounted in the upper portion thereof to which edible oil is fed throughinput fitting 21. Flow line 22 having back pressure valve 23` thereonpasses the edible oil t-o be dehydrated and deaerated to fitting 21.Prime mover 24 operates to rotate the spray device (if it is a rotor) ata predetermined velocity. The spray device employs an aligned liporifice of less than 0.020 inch in a manner to be described. Vacuumtting25" is attached ticles which coalesces on the vessel walls andpasses down to the sump from where it is taken from fitting 26 by line28.

Motivated by pump 29, the foil is passed through line 30 to filter press31 controlled, as well, by valve 32 connected to liquid level control 33on vessel 19. In filter press 31, the remaining diatomaseous earth,clay, activated charcoal or other decolorizing substance is removed fromthe oil and it is then passed through line 3'4 to the deodorizing step.

Line 34 joins recycle line 35 which passes to heat exchanger 36. Thelatter raises the oil to a temperature necessary for deodorization.Temperature range control 37 connects to the heat exchanger steam inputline 38 and output line 39 from the heat exchanger. Back pressure valve40 is positioned on line 39 between the heat exchanger and the inputfitting 41 of the first deodorizer flash evaporator 42. Back pressureValve 40, as is the case in back pressure valves Z3 already describedand 58 to be described, are entirely conventional in nature and operateto hold a back pressure in the line behind same. The valves move towardwide open position in each case with increasing pressure. Thus it isproportionately controlled by the pressure in the line feeding it at apoint immediately upstream of the valve. Each valve typically contains,in the cap thereof, a diaphrgam connected to a spring loaded valve stem,with pressure transmitted through the overhead line on the side of thediaphragm away from the valve.

Evaporator 42 is of substantially the same construction as evaporator 19with .the exception that the body portion thereof is of greater volumewhereby to permit the time control procedure to be described. Primemover 43 rotates rotor 44 or a static spray head having an aligned liporifice in the critical range of 0.002 to 0.020 inch. Vacuum line 45joins vacuum line 27' in common line 46 passing to conventional sourceof vacuum 46a. A hollow perforated ring 47 may be provided, fed by mainsteam input line 48. Main steam line feeds secondary lines 48a (to ring47) and 4gb, the latter controlled by valve 48e and joining line 39after valve 40. Output fitting 49 feeds output line 50 having pump 51thereon. Control valve 52 on line 53 is connected to liquid levelcontrol 54 on the side of vessel 42. Recycle line 5S connects to line 35which passes to heat exchanger 36.

The function of the rst deodorizer section will now be described. Theedible oil passing through the heat exchanger 36 is raised to thetemperature necessary for deodorization and for fatty acid-productionand distillation. Steam may be added through line 48!) before dispersalto aid volatile extraction. The oil (and optional steam) is dispersedthrough the critical form and size orifice of the rotor or spray head 44in a finely divided mist under vacuum conditions. The steam inputthrough ring 47 strips the droplets thereabove of undesirable volatileconstituents which are drawn off through line 45 with the steam. Bottomsare drawn off through line 50 and pump 5l, discharge flow from the firstdeodorizer section being controlled by valve 52 hooked to liquid levelcontrol 54. Valve 52 controls the quantity of recycle for successivepasses through the rotor 44 whereby to build up a resident body ofedible oil in the vessel 42. The throughput of the first deodorizersection is balanced with the resident volume to provide a carefullyregulated residence time in the vessel 42. A typical recycle-throughputratio would be 9 to l, whereby only one-tenth of the oil through line 53would have had only one pass through the rotor. A very large evaporatormight permit up to say, 49 to l recycle, but, nevertheless, one-fiftiethof the product would have had only a single pass through the evaporatorrotor. As a very small amount of nondeodorized foil will contaminate avery large quantity of deodorized oil, we have concluded that a minimumof two passes through a rotor for all of the oil and a minimum quantityof the oil having had but two passes is required for effectivedeodorization.

From the first deodorizer section line 53 passes to line 55a of thesecond deodorizer section, the latter running to heat exchanger 56.Temperature range control 57 and back pressure valve 58 are provided online 59 connecting to the input fitting 60 of second deodorizer sectionevaporator 6l. Evaporator 61 is the saine in structure and operation asevaporator 42 with prime mover 62 driving rotor 63, vacuum fitting 64,liquid level control 65, steam input ring 66 and output fitting 67 atthe bottom of the vessel. Main steam input line 66a feeds ring 66through line 66b and optionally passes steam to line 59 after valve 58through line 66e controlled by valve 66d. Vacuum line 68 is connected totting 64, while output line 69 has pump 70 thereon, from which dischargeline 71 runs. Control valve 72 is connected to level control 65, whilerecycle line 73 connects to lines 53 and 55a.

The function of the second deodorizer section is identical to that ofthe first and cumulative therewith. The input edible oil from dischargeline 53 is maintained at the desired temperature by heat exchanger 56and distributed with or without added steam in a fine particle sprayinto vacuum Zone in vessel 6l through an aligned lip orifice of lessthan 0.020 inch width. Stripping steam removes undesirable volatilesthrough line 63. Bottoms from flash evaporator pass through line 60 torecycle or the next stage. A body of edible oil is maintained in thevessel 61 by suitable control through valve 72 whereby to give acarefully regulated treating time.

Only two deodorizer sections are shown. This is conceived as adequate.However, additional sections would yet further improve the quality andproduct control. It should be noted in two identical deodorizersections, with a 9 to l recycle in each, one one-hundredth of theproduct will have only two passes. With the addition of another section,one one-thousandth of the product would have at least three passes andthe remainder a greater number. Economics limit the number of deodorizersections possible. Final stage could, or possibly should, be only singlepass.

Line 74 passes the deodorized oil to cooler 75 and from thence by line76 through an additive stage represented by line '77, mixer 77a and backpressure valve 78 to vessel 79, where a body of finished edible oil isstored under vacuum, the latter taken off through line S0. Liquid levelcontrol Sl, connected to valve 82 on discharge line 83a having pump 84-thereon, regulates the volume of oil fin the vessel. Line may ,beconnected to a common line 85 to which line 63 is connected. Or, allvacuum lines in the entire system may be connected to a single vacuumsystem. From vessel 79, the edible oil is passed to final storage,packaging, etc.

The key to the instant system is in the deodor-izer section where atleast one recycle flash evaporation unit is employed. A minimum numberof two recycle flash evaporator units with steam stripping of at leastone is presently projected. The pressure of the flash evaporator 19provides an optimum system which will deaerate and dehydrate moreeiciently than any present existent system. However, the deodorizersystem alone without evaporator 19 will process conventionally preparedand conventionally deaerated oil to a finish level above presentpractice. In the deodorizer section, there are two critical variables.In the first place, sufficient residence time must take place at thecritical temperature at which fatty acids form to achieve equilibriumbetween their rate of formation and rate of removal through lines 45 and68. Secondly, there inust `be sufficient passes through the rotor [forall or at least substantially all of the oil to be efficiently andeffectively deodorized by the steam. As above mentioned, two recycleevaporators of the character described are projected as required.

FIGS. 2-4, inclusive, show a rotating spray device employed in a lowpressure vessel as i9, 4t2 and `61, which will be first described. FIG.5 shows a nonrotating spray head adaptable for use in like low pressurevessels.

The operation of the apparatus of FIGS. 2 4, inclusive, consists in theimpartation of high rotative velocity or enengyv to a fluid mixture bymeans of an atomizin-g rotor, the rotor consisting of a liquidaccelerating disc and a shrouding disc spaced apart to form a narrowannular space therebetween wi-th a narrow orifice of critical width`defined at the periphery thereof. The fluid mixture to be separated isintroduced to the annular space Ibetween the discs and projected at highvelocity from its periphery through the critically sized and shapedorifice. Separation of the flashable component or cornponents from themixture is effected byl imparting suicient energy to atomize the mixedflui-d through the limited orifice in such manner as to provide arelatively maximum surface per unit volume of the fluid and sufficientinternal energy to the particles to provide driving force for requiredmass. The transfer dispersal of the fluid takes the form of a continuoushorizontal spray of high velocity, greatly energized, mist particles ofmicrodimensions extending from the orice of the energizing atomizingrotor to the shaped inside wall of the enclosing vessel where theycoalesce.

Referring to FIGS. 2 4, and particularly to FIG. 2, at `36 is shown avessel having an upper portion 85a of its wall inclined both upwardlyand inwardly relative to the interior of the vessel, relatively verticalside walls, and a lower wall portion 86h inclined both downwardly andinwardly relative t the interior of the vessel. On

top of the vessel 86 is a motor mounting 87 which supports the motor 88.Referring particularly to FlG. 3, opening 89 is formed in the top centerportion of the vessel 86 and receiving rim 90 is circumferentiallyfastened thereto -by welds or other attachments 91. Mounting plate 92 isfixed within the rim 90 by bolts 93. The motor mounting 87 is welded orotherwise fixedly attached to the mounting plate 92 by` attaching meansor welds 94. Shaft 95 is a continuation of or fixed to the drive shaftof the -motor 88 and |may be )driven in rotation thereby. Plate 92 hasopening 96 centrally thereof. Support tube 97 is fixed to the plate 92by bolts 98, ex-

tends therethrough, and has fitting 99 extending fromone side thereof aswell as recessedlportions 100' at the lower end thereof. Pipe 101 issupported by bolt 102 relative to the support tube 97 and surroundsshaft 95 with sleeve bearing 103 fixed to the inside surface thereof tomaintain the shaft 95 in` position relative thereto. Feed annulus 104between the outside of the pipe 101 and the inner surface of tube 97connects at its upper end with the bore of the fitting 99 to permit feedof the fluid to be flask evaporated or vacuum separated therefrom.

Acceleratingdisc 105 forming the ilo-wer surface of the atomizingroto-r, has opening 106 centrally therethrough to receive :a lesserdiameter portion 95a of shaft 95 therethrough. Nut 95b enga-ges thethreaded bottom portion 95C of the shaft 95 and fixes the acceleratingdisc relative to the end of the shaft. The upper central portion of theaccelerating disc ab-uts the under surface of the slightly greaterdiameter portion 95d of shaft 95. -The upper surface of the acceleratingdisc is also recessed as at 105a to permit positioning of the lower endof the pipe 101 in close association therewith. Disc 105 is preferably`angled slightly upwardly in cross section as it extends outwardly fromthe central portion thereof. Shrouding disc 107, forming the vupperportion of the atomizing rotor, is fixed by -bolts 108 (FIG. 4) toaccelerating vanes 109 which in turn are fixed to accelerating disc 105.Shrouding disc 107 is preferably substantially horizontal in crosssection, that is, fixed essentially `at night angles to shaft 915.Shrouding disc 107 has upwardly extending central portion 107a which isrecessed or indented to permit semi-engagement of tube ciently to permitrotation of the shrouding disc relative tube 97 and pipe 101 withoutcontact therewith.

The annulus or space 110i between the accelerating and shrouding discsconnects at its inward end 'with annulus 104 between pipe 101 and tube97 to permit -feed of liquids or fluids to be stripped or flashed intothe rotating disc where vanes 109 will pump it through the orifice 111.The orifice 111 at the periphery of the two discs, to effectivelyoperate to properly disperse the fluids, must be formed by two edgeswhich are essentially (vertically) in line and not overtwenty-thousandths of an inch apart. We have discovered that if eitherthe periphery of the shrouding disc or the periphery of the acceleratingdisc extends past the other or the orifice therebetween exceeds 0.020inch, the apparatus will not effect sufficient dispersal of the liquidor fluid tobe stripped or flashed. The upward angling of theaccelerating disc or, indeed, the relative angle of either disc relativeto the shaft 95, is not critical, provided the peripheries of both discsare essentially Vvertically in Iline and the orifice is of an aperturein the range of two to twenty-thousandths of an inch. One one-hundredthof 1an inch is about optimum gap -for -most edible oils.

Referring to FIG. 2, legs 112 support the vessel 86V and an opening ispositioned preferably centrally of the bottom of the vessel withdraw-off line 113 leading therefrom with pump 114 connected thereto.Vacuum line 115 draws preferably from the top portion of the vessel.Steam or any other inert gas may be supplied to the vessel through pipe116 and is preferably introduced beneath the atomizing disc through ahollow perforated ring 117. At any rate the vacuum takeoff should be onthe opposite side of the spray from the steam input.

In operation of the FIGS. 2-4 modification, the fluid to be flashed orstripped is introduced through line 118 (22, 39 or 59) to fitting 99where it passes down annulus 104 and into space 110 between theshrouding and the accelerating discs. In the throat of the rotor, thefluidv is picked up by vanes 109 and the rotation of the discs by shaft95 moves the fluid outwardly where it is projected through orifice 111lin the form of mist particles of microdirnensions which travel from theorifice to impige upon the upwardly and inwardly slated portion 86a ofvessel 86. The rotor must most preferably be positioned so the particlesimpinge on the upwardly and inwardly inclined surface 86a and not thevertical portions thereof whereby the outward momentum of the particlesmay be transformed into downward momentum. The volatile constituents areevaporated from the finely divided energized mist particles during thetraverse. The volatiles-,in the form ofwater Vapor, gases and the likeare withdrawn from the confined space within the vessel through vacuumoutlet 115 which is connected to a vacuum head, not shown. The vacuum inthe vessel is normaly controlled within the range of Yone-quarter inchto ten inches of mercury 4absolute pressure depending upon the finalwater content or other volatile or odoriferous contentv desired in thefluid being treated.

We have conclusively established that an extension of the lip of eitherthe shouding or accelerating disc as in conventional rotors or theprovision of an orifice of greater width than twenty-thousandths of aninch, with or Without such extension, will substantially inhibitsuccessful operation in the rotor in edible oil processing and makesubstantially more diflicult the accomplishment of the objects of theinvention.

Referring to FIG. 5, showing a static spray head, opening 119 is formedin the top center portion of the vessel shell 120 and mounting plate121, having centra-l yopening 122 therein, is fixed to the enlargedportion 119a of opening 119 by bolts 123. Shrouding disc 124 is fittedby its upwardly-extending portion 125 into opening 122. L-tting 126 hasperipheral flange 127 at its lower end which is engaged by bolts 128which also engage threaded openings in the upper ange portion 124g ofthe shrouding disc 124. A lower disc 129 has bolt openings 130 arrangedperipherally of its outer edge to match openings 131 in the shroudingdisc 124. A lower disc 129 has bolt openings 130 arranged peripherallyof its outer edge to match openings 131 in the shrouding disc. Lowerdisc 129 is fixed relative to shrouding disc 124 by two constructions.In the first place, limit stops 132 limit the allowed closeness of thetwo discs while bolts 133 extend through openings 131 and 130 and havesprings 134 encircling the bolts and regulated in compression againstthe underside of lower disc by nuts 135 and washers 136 threaded on thelower ends of bolts 134. The upper heads of the bolts 133 as shown at133:1 rest on leveling abutment 136 formed on the shrouding disc. Vacuumtakeoff in this construction may comprise exhaust pipe 137 whichoptionally extends out the side wall of the vessel with its intake endpositioned centrally under lower disc 129 as seen in FIG. 5.

Lower disc 129 has upwardly-extending central portion 129a to guide theinput fluid uniformly outwardly in the channel 138 formed between thetwo discs. The required pressure for forcing the uid outwardly betweenthe annulus 139 defined by the vertically aligned outer disc edges ofthe modification of FIG. 5 depends largely on the viscosity thereof. Thepressure must be sufficient to drive the material outwardly through theorifice between the two discs so as to impinge at high velocity on theknuckle radius (downwardly curved Wall) of the vessel. The crucial rangeorifice gap must be maintained within the tWo-thousandths (0,002) of aninch to twenty-thousandths (0.020) of an inch range previously set forthrelative the rotor modification.

From the foregoing it will be seen that this invention is one welladapted to attain all of the ends and objects hereinabove set forthtogether with other advantages which are obvious and which are inherentto the structure.

It will be understood that certain features and subcombinations are ofutility and may be employed without reference to other features andsubcombinations. This is contemplated by and is within the scope of theclaims.

As many possible embodiments may be made of the invention withoutdeparting from the scope thereof, it is to be understood that all matterherein set forth or shown in the accompanying drawings is to beinterpreted as illustrative and not in a limiting sense.

Having thus described our invention, we claim:

1. Apparatus for stripping liquids comprising, in combination, a 110Wline, said flow line communicating to a vessel defining a zone ofreduced pressure, a reduced orifice spray device in said vessel zone ofreduced pressure connected to said ow line operable to disperse saidliquid in finely divided particles therein, a liquid level control onsaid vessel, a vacuum line from said vessel above said spray devicetherein, a liquid withdrawal line from the lower portion of said vessel,a recycle line passing from said Withdrawal line to said fiow linecommunicating to said spray device, a back pressure valve on said flowline comunicating to said spray device down stream of the recycle lineconnection therewith, a control valve on `said Withdrawal line past saidrecycle line connection actuated by said liquid level control, and pumpmeans on said Withdrawal line between the recycle line connection andthe vessel.

2. Apparatus as in claim 1 including a second vessel defining a secondZone of reduced pressure therein, a second flow line connected to saidfirst vessel withdrawal line past said control valve thereon and passingto said second vessel, a second reduced orifice spray device in saidsecond vessel to distribute liquid in a line dispersed spray into saidsecond vessel connected to said second flow line, a second vacuum lineconnected to said second vessel, a second liquid level control device onsaid second vessel, a second withdrawal flow line from said secondvessel, a second recycle line connected to said second withdrawal lineand joining the said second `flow line to said second vessel, a backpressure valve on said second ow line downstream of the recycle lineconnection therewith, a second control valve on said second withdrawalline downstream of said second recycle connection operated by saidsecond liquid level control, and pump means on said second withdrawalline up stream of said recycle line connection.

References Cited in the file of this patent UNITED STATES PATENTS378,843 Lillie Feb. 28, 1888 1,398,735 MacLachlan NOV. 29, 19211,831,892 Thompson Nov. 17, 1931 2,103,887 Bowen et al Dec. 28, 19372,300,985 Smith NOV. 3, 1942 2,368,049 Stratford Jan. 23, 1945 2,489,509Straight Nov, 29, 1949 2,621,196 Thurman Dec. 9, 1952 2,674,609 Beal etal. Apr. 6, 1954 2,734,565 Lockman et al. Feb. 14, 1956 2,796,120Lockman lune 18, 1957 2,838,135 Pilo et al. June 10, 1958 2,919,232Stingley Dec. 29, 1959 2,931,433 Mertz Apr. 5, 1960 2,990,011 StratfordJune 27, 1961

1. APPARATUS FOR STRIPPING LIQUIDS COMPRISING, IN COMBINATION, A FLOW LINE, SAID FLOW LINE COMMUNICATING TO A VESSEL DEFINING A ZONE OF REDUCED PRESSURE, A REDUCED ORIFICE SPRAY DEVICE IN SAID VESSEL ZONE OF REDUCED PRESSURE CONNECTED TO SaID FLOW LINE OPERABLE TO DISPERSE SAID LIQUID IN FINELY DIVIDED PARTICLES THEREIN, A LIQUID LEVEL CONTROL ON SAID VESSEL, A VACUUM LINE FROM SAID VESSEL ABOVE SAID SPRAY DEVICE THEREIN, A LIQUID WITHDRAWAL LINE FROM THE LOWER PORTION OF SAID VESSEL, A RE- 